In the last few days, Hurricane Sandy has killed at least 78 people – now, as I come back on a fact-checking pass, 82.

Here’s Bangladesh, home of 160,000,000 people:

This picture is about 750 km (450 mi) on a side. Bangladesh is the area of New York State. It has the highest population density of any country except micronations like Singapore and the Vatican.

Notice there is no patchwork logging texture like most of the developed world has from space. Bangladesh’s only remaining lowland forests of any size are the Sundarbans, a dark green mangrove swamp on the coast. Except some foothills around the edges, the country is almost entirely a dense network of villages between fields and ponds. More than two thirds of its people – roughly the equivalent of the entire population of Japan or Mexico – live outside cities. If you pull it up on Google Maps, you’ll see many ponds have been squared off as surrounding farm plots crowded at their edges over centuries.

Notice the braided rivers. These are the members of the Ganges river system. Rivers can only flow in that kind of pattern on flat land. The land is flat because it is mostly the delta of the Ganges. Soil from the mountain range at the top of the frame, the Himalaya, washes down the rivers and has slowly built a bay into a huge bench along the Indian Ocean. About a third of Bangladesh is below 10 meters. The Sundarbans are legally protected partly because they buffer storm surges: when a cyclone makes landfall, the seawater it pushes is slowed by the manifold roots. This was learned the hard way.

Notice two cities – lichen-like gray patches. The one in the lower center of the frame is Dhaka (Dacca); 15 million people live there, or a little less than twice as many as in the five boroughs of New York City. To its southwest, not far from the water, is Kolkata (Calcutta), just over the border in India, with a population of about 14.5 million. Both of them are roughly half below 10 meters.

The border with India is winding and sometimes contentious. One of the main disagreements is sharing the water of the Ganges. The Ganges depends on the monsoons and snowfall in the Himalaya. The area is politically complex. To the west, India, a nuclear-armed democracy, plays a difficult set of roles in the world and is not always friendly. To the north, past the tiny Himalayan countries, is China, a nuclear-armed single-party state and rival of India. To the east is Myanmar, a terribly oppressive dictatorship. Bangladesh would soon find itself in trouble if many of its people, even a small proportion like ten million, spilled across any of its borders. As I write this, I see that the UN High Commission on Refugees has in fact just asked Bangladesh to open its borders to people leaving Myanmar.

Bangladesh’s Human Development Index is comparable to that of Cambodia or Angola, two countries that suffered generation-long episodes of violence near the end of the last century, but Bangladesh has been basically at peace since the year-long war of independence in 1971. It is simply very poor. It’s getting richer, but it’s very poor. The nation cannot afford to, say, take the approach of the Netherlands and wall out the ocean, even if that were possible in a country of rivers. Now, for all its challenges, Bangladesh has well-chosen strategies to deal with them. It is not powerless and it is not a lost cause. But it is 160,000,000 people living under a threat that, so far, only increases.

Climate change is slippery for many reasons. One is that it’s hard to explain what warming actually means. If everywhere on Earth were a few degrees warmer and nothing else changed, we would be fine. But warming puts more energy in the climate, which is not a linear equation. We only know the basics of the system: for example, how greenhousing works. We don’t have good models even of extremely important things like monsoons, so climate change is rolling dice we can’t see. We do know we are in for rising sea levels and more energetic tropical cyclones. Part of the rich world has just been reminded what that means.

I am politicizing. I am using these dead people in the Caribbean and the Eastern Seaboard, who cannot speak for themselves, and these 160,000,000 living Bangladeshis, who can speak for themselves, to make my own point. I’m doing it because I think the point is sound and important.

Climate change is hard for many reasons. Wisely did Al Gore call it an inconvenient truth, because this is how many people have dealt with it: by arguing that it isn’t happening because if it were it would be too hard to fix. By too hard to fix, they mean we would need an intergovernmental system to stop it. They don’t like intergovernmental systems because they violate the principle of subsidiarity – that power should be held at the lowest level possible to do its work. But the proper locality for dealing with atmosphere-driven climate change is in fact the planet. This is hard for people who see a world with dragons in the oceans. In a more mapped and encircled world, we have different tools and different risks. 2012’s dragons are not the unknowability of spaces, but of systems. They are the probabilities of fires, floods, famines, and refugees.

We should rarely try to predict the whole world’s future – to plan as if we have any idea what politics will be like in 50 years. I think of Feynman saying it is our responsibility to leave the people of the future a free hand. This suggests that we should be very cautious about setting up regulatory systems that might be abused by the powerful of decades and centuries to come: frameworks that start with excellent ideas but slowly turn to covering force and scouring out difference. This is a point that we hear loudly from the right about carbon taxes, but I don’t think it’s partisan at root; for example, we hear it from the left against many international trade and finance institutions. I agree in some instances and not others. We have to weigh it, in this case, against another kind of freedom for the future: a hospitable world of fed people who are where they want to be.

It’s no good talking about the climate tipping point. The climate is a thing in motion and it never stays on any path. Maybe we are too late to avoid millions of refugees; maybe we have another five years. Maybe we will thread a gap in the dragons by chance; maybe the only one out there will take us. It doesn’t help to worry, because we know what we can do and that sooner is better.

I remember what a friend quoted to me just after a certain political celebration four years ago, from William Morris’s Dream of John Ball:

I pondered all these things, and how men fight and lose the battle, and the thing that they fought for comes about in spite of their defeat, and when it comes turns out not to be what they meant, and other men have to fight for what they meant under another name.

Everything will change. The climate, our response, and my response to our response will be different in twenty years. It will never be solved. People will still die of one thing or another. There will be politics, valid and not, and wildfires, preventable and not. We have no cause to imagine that there’s an easy way to keep billions of humans healthy on a healthy planet. But we can free their hands. We can be, in Salk’s phrase, good ancestors.

There are many scenarios. The one I like best is where large groups of well-informed people, openly and as consensually as possible, accepting differences of motivation and style, build climate stewardship into the economic systems of our species.

I won’t leave you with an act now! message. I would rather you didn’t think of this as an external goal, but as something you bring everywhere – to work, in public – the way you might carry any other serious ethical commitment. The right time to start politicizing the climate is whenever you do it.